Driving mechanism.



H. L. JOHNSTON. DRIVING MECHANISM. APPLICATION rum) APR. 5, 1909.

Patented Mar. 1, 1910.

UNITED STAIEEiETENT OFFICE.

HERBERT L. JOHNSTON, OF TROY, OHIO, ASSIGNOR TO THE HOBART ELECTRICMANU- FACTURING COMPANY, OF TROY, OHIO, A CORPORATION OF OHIO.

DRIVING MECHANISM.

Specification of Letters Patent.

Patented Mar. 1, 1910.

Application filed April 5, 1909. Serial No. 487,903.

To all whom it may concern:

Be it known that I, HERBERT L. JOHNSTON, a citizen of the United States,residing at Troy, in the county of Miami and State of Ohio, haveinvented certain new and useful Improvements in Driving Mechanism, ofwhich the following is a specification.

This invention relates to improvements in driving meohanisin especiallyadapted to grinding mills, but it may be employed in connection withother classes of machinery.

The object of the invention is to provide simple and effective means bywhich the driving mechanism of the machine may be automaticallydisconnected from the driven parts in case any foreign substance whichwould be liable to injure the parts should be fed into the machine.

The invention consists in the constructions and combinations of partshereinafter described and set forth in the claims.

In the accompanying drawings, Figure 1 is a longitudinal sectional viewof a grinding mill embodying my invention. Fig. 2 is a longitudinalsectional view of the driving shaft and conveyor showing the connectionbetween the same. Fig. 3 is a side view of the same parts. Fig. 4 is adetail of the end of the conveyer. Figs. 5 and 6 are details of a partof the driving connection.

Like parts are represented by similar characters of reference in theseveral views.

In the present case I have shown my improvement applied to a coffeemill.

at represents the outer casing, having in the upper part thereoftheusual hopper, a which casing may be constructed in any usual andsuitable manner.

Z) is the driving shaft, which is connected to any suitable source ofpower, preferably by a slip connection so that the shaft may be adjustedlongitudinally by any suitable means so as to vary the relation of thegrinding burs with respect to each other.

0 represents the stationary grinding bur, which is secured to the casingin any suitable way, and 0 represents the movable grinding bur,screw-threaded on the driving shaft, as shown.

In the present type of machine there is employed a conveyer, cl, looseon the driving shaft and located in a chamber, o in the casing, whichchamber leads from the bottom of the hopper to the grinding burs, sothat the contents of the hopper will be fed to the burs by the conveyer.This conveyor is normally connected to the shaft by a pin, 6, located ina transverse opening through the shaft, and having a lateral projection,c, which engages in a recess, (2 in the end of the conveyer. This pinhas a flat face, 6, midway its length and in line with the projection cNormally spring-pressed into ongagement with this face, by a spring, 0,is a head a the spring and head being located in a chamber, a, in theshaft, through which chamber the pin, 0, extends. The engagement of thehead with the pin prevents the pin from rotating in the shaft underordinary conditions, so that the engagement of the pin with the conveyorwill be maintained to cause the parts to rotate together, the tension ofthe spring being sufficient to maintain this engagement under theordinary strain of the grinding operation. In case any foreignsubstance, such as a piece of metal, is fed to the conveyor, theresistance will be such as to permit the pin to turn in the shaft byforcing the head from its face against the tension of the spring, andthus disconnect the conveyor from the shaft. It will be understood thatthe recess, 0 in the end of the conveyor will be of such size as topermit the projection to pass freely therefrom when the pin turns.

Having thus described my invention, 1 claim:

i. In a device of the character described, a shaft, a rotatable partloose thereon, a rotatable device extending through said shaft andnormally detachably connected with said rotatable part, and a springnormally holding said device from rt'itating in said shaft,substantially as specified.

2. In a device of the character. described, a shaft, a rotatable partloosely mounted on said shaft, a pin extending loosely through saidshaft, a lateral projection on said pin extending into a recess in saidrotatable part, and spring-pressed means for holding said pin fromrotation, substantially as specified.

3. In a device of the character described, a shaft, a rotatable partloosely mounted. thereon, a rotatable pin extending loosely through saidshaft, a lateral projwtion on said pin extending into a recess in saidrotatable part, a flat face on said pin, and a head spring-pressedagainst said face, substantially as specified.

4:. In a device of the character described, said pin and rotatable part,a chamber in a shaft, a rotatable part loosely mounted said shaft, aflat face on said pin in said thereon, a rotatable pin extending throughchamber, and a head located in said chamber said shaft, a detachableconnection between spring-pressed against said face, substan- 15 5 saidshaft and rotatable part, a flat face on tially as specified.

said pin, and a head spring-pressed against In testimony whereof, I havehereunto said face, substantially as specified. set my hand this 2nd dayof April, 1909.

5. In a device of the character described, HERBERT L. JOHNSTON. a shaft,a rotatable part loose thereon, a Witnesses: 10 rotatable pin extendingthrough said shaft, E. E. EDGAR,

a detachable driving connection between J. S. CoMBs.

